/* 1.1.2: Fixed a bug where trailing . in e-mail address was passing
            (the bug is actually in the weak regexp engine of the browser; I
            simplified the regexps to make it work).
   1.1.1: Removed restriction that countries must be preceded by a domain,
            so abc@host.uk is now legal.  However, there's still the 
            restriction that an address must end in a two or three letter
            word.
     1.1: Rewrote most of the function to conform more closely to RFC 822.
     1.0: Original  */




function emailCheck (emailStr) 
	{

	/* The following pattern is used to check if the entered e-mail address
   	fits the user@domain format.  It also is used to separate the username
   	from the domain. */

var emailPat=/^(.+)@(.+)$/

	/* The following string represents the pattern for matching all special
   	characters.  We don't want to allow special characters in the address. 
   	These characters include ( ) < > @ , ; : \ " . [ ]    */

var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"

	/* The following string represents the range of characters allowed in a 
   	username or domainname.  It really states which chars aren't allowed. */

var validChars="\[^\\s" + specialChars + "\]"

	/* The following pattern applies if the "user" is a quoted string (in
   	which case, there are no rules about which characters are allowed
   	and which aren't; anything goes).  E.g. "jiminy cricket"@disney.com
   	is a legal e-mail address. */

var quotedUser="(\"[^\"]*\")"


	/* The following pattern applies for domains that are IP addresses,
   	rather than symbolic names.  E.g. joe@[123.124.233.4] is a legal
   	e-mail address. NOTE: The square brackets are required. */

var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/

	/* The following string represents an atom (basically a series of
   	non-special characters.) */

var atom=validChars + '+'

	/* The following string represents one word in the typical username.
   	For example, in john.doe@somewhere.com, john and doe are words.
   	Basically, a word is either an atom or quoted string. */

var word="(" + atom + "|" + quotedUser + ")"

	// The following pattern describes the structure of the user

var userPat=new RegExp("^" + word + "(\\." + word + ")*$")

	/* The following pattern describes the structure of a normal symbolic
   	domain, as opposed to ipDomainPat, shown above. */

var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")


	/* Finally, let's start trying to figure out if the supplied address is
   	valid. */

	/* Begin with the coarse pattern to simply break up user@domain into
   	different pieces that are easy to analyze. */

var matchArray=emailStr.match(emailPat)

if (matchArray==null) {

  	/* Too many/few @'s or something; basically, this address doesn't
     	even fit the general mould of a valid e-mail address. */

	alert("Email parece incorreto. Verifique arrobas (@) e pontos.");
	return false;

}

var user=matchArray[1]
var domain=matchArray[2]

	// See if "user" is valid 

if (user.match(userPat)==null) 
{
    	// user is not valid
    	alert("Email invalido - erro antes do arroba (@). Verifique espacos em branco e caracteres invalidos.");
    	return false;
}


	/* if the e-mail address is at an IP address (as opposed to a symbolic
   	host name) make sure the IP address is valid. */

var IPArray=domain.match(ipDomainPat)

if (IPArray!=null) {

    // this is an IP address

	  	for (var i=1;i<=4;i++) 
		{

		    	if (IPArray[i]>255) 
			{

	        	alert("Endereco IP invalido como dominio do email.");
			return false;

	    		}
    		}
    return true;
}

// Domain is symbolic name

var domainArray=domain.match(domainPat)

if (domainArray==null) 
{

	alert("Erro no email (apos o arroba - @): Dominio invalido.");
    	return false;

}

	/* domain name seems valid, but now make sure that it ends in a
   	three-letter word (like com, edu, gov) or a two-letter word,
   	representing country (uk, nl), and that there's a hostname preceding 
   	the domain or country. */

	/* Now we need to break up the domain to get a count of how many atoms
   	it consists of. */

var atomPat=new RegExp(atom,"g")
var domArr=domain.match(atomPat)
var len=domArr.length

if (domArr[domArr.length-1].length<2 || 
    domArr[domArr.length-1].length>4) {
	
	   	// the address must end in a two letter or three letter word.

	   	alert("Email invalido: emails devem terminar: \n - com extensoes de pais (.br para Brasil, .fr para França, .de para Alemanha etc.) \n - OU com extensoes de dominios (.com , .edu , .net , .org  etc.)");
   		return false;

	}

// Make sure there's a host name preceding the domain.

if (len<2) {

   var errStr="Endereço incompleto: falta o domínio!"
   alert(errStr)
   return false

}

// If we've gotten this far, everything's valid!

return true;

}